Move description section

Author: IvanGoncharov

spec/Section 3 -- Type System.md

@@ -179,7 +179,7 @@ made available via introspection.
 
 To allow GraphQL service designers to easily publish documentation alongside the
 capabilities of a GraphQL service, GraphQL descriptions are defined using the
-Markdown syntax (as specified by [CommonMark](https://commonmark.org/)). In the
+Markdown syntax (as specified by [CommonMark](http://commonmark.org/)). In the
 type system definition language, these description strings (often {BlockString})
 occur immediately before the definition they describe.